Stop for electric drills



NOV. l1, 1947. D, N, GOLDBERG 2,430,812

STOP FOR ELECTRIC DRILLs Filed Sept. 24, 1945 2 Sheets-Sheet 1 D. N. GOLDBERG STOP FOR ELECTRICDRILLS Filed Sept. 24, 1945 2 Sheets-Sheet 2 o 0 l0 ff? Nov. 11, 1947'.

,1 IiI Patented Nov. 11, 1947 UNITED STATES PATENT oFFlcE STOP FORELECTRIC DRILLS David N. Goldberg, Wheeling, W. Va. Application September 24, 1945, Serial No. '618.297,

4 Claims. l

This invention relates to improvements in hand drills and more particularly to an attachment for a Howard hand drill for limiting the movement of the bit into the work.

An object of this invention is' to provide an improved adjustable stop means which may be mounted on a conventional powered hand drill which will provide for limiting the drilling of the bit into the work.V

Another object of this invention is to provide an attachment of this kind which can be mounted on the motor housing ofla hand drill and disposed in a position to limit the extension of the drill into the work so that holes of desired depth can be drilled accurately with the hand drill.

Another object of this invention is to provide a device of this kind which acts as a steadying means to steady the drill and maintain the drill at right angles to the work.

A further object of this invention is to provide a device of this kind which can be accurately calibrated with respect to the drill so that the movement of the drill into the work will be stopped after a hole of a predetermined depth has been formed. v

With the foregoing objects in view, and others which may hereinafter more fully appear the invention consists of the novel construction, combination and arrangement of parts, as will be more speciflcally described, and illustrated ln the accompanying drawings, wherein are shown embodiments of the invention, but it is to be understood that changes, variations and modications may be resorted to which fall within the scope of the invention, as claimed.

In the drawings:

Figure '1 is a detail side elevation of a hand drill having a stop means mounted thereon, according to an embodiment of this invention.

Figure 2 is a detail rear elevation, partly in vertical section, of the device.

Figure 3 is a detail side elevation, partly broken away, and in vertical section. of the device.

Figure 4 is a detail top plan of the device.

Figure 5 is a bottom plan of the device.

v Figure 6 is a fragmentary sectional view taken on the line 6-6 of Figure 1.

Figure 7 is a fragmentary sectional view taken l on the line 1-1 of Figure 4.

Referring to the drawings the numeral III designates generally a hand drill which includes a 2 tively connected through gear means with the motor I I. A drill bit I5 is adapted to be engaged with the chuck I4 for drilling a hole n a workpiece I6.

In order to provide a means whereby the movement of the drill bit I5 may be limited with respect to the workpiece I6, I have provided a stop meanswhich includes a base plate I1, secured by fastening members I8 to the lower side of the motor II and rearwardly of the housing I2. The plate I1 has extending downwardly therefrom a pair of guide bars I9 which may be threaded or otherwise firmly secured to the plate I1 the guide members I9 having slidable thereon tubular members 29. The slide members 20 are each provided with an annular rib 2I, between the ends thereof, and a spring 22 is disposed within each slide member 2B, and bears at its upper end against a guide member I9. A plug 23 is threaded into the lower end of each slide member 2D, and bears against the lower end of the spring 22. A bar 24 is provided with a. pair of openings 25 within which the tubular members 20 slidably engage, and the tubular members 20 are limited in their downward movement by means of a, U-shaped locking member 26 which engages in an annular groove 21 formed in the tubular member 20, adjacent the upper end thereof.

A locking member 26 is adapted to bear against the upper side of the bar 24 so' as to thereby limit the downward movement of the tubular member 20. The bar 24 provides adjustable stop means for limiting the sliding movement of the two tubular members or slides 2l), and the bar 24 is adjusted lwith respect to the base plate I1, by means of a threaded shaft 2B. The shaft 28 is disposed between the two guides I9 and is provided adjacent the upper end thereof with a knurled wall 29 by means of which the shaft 28 may be manually rotated.

The shaft 28 is provided with a hand wheel 29 with a stud 30 which is rotatable through an opening 3l formed in the plate I1, and the plate I1 is formed with a recess or counter bore 32 extending downwardly from the upper side thereof. A washer 33 ls disposed about the stud 30 in the recess or counter bore,32 and a cotter pin 34 is extended through the stud 30 above the washer `33 so that the shaft 2B will be held against endwise movement and at the same time permitted to freely rotate relative to the plate I1.

A lower plate 35 is disposed at the lower ends of the slide members '20, and is provided with openings 36 through which the plugs 23 engage, and the plugs 23 are provided with pointed heads housing I2 includes a chuck I4 which is opera- 65 31 below the plate 35. 'Ihe plate 35 is also pro- 3 vided with a U`shaped cutout-38 which forms an opening through which the drill bit I5 is adapted to loosely extend. The plate 35 is also provided with a pair of feet 39 at the ends of the U-shaped member, formed by the cutout 38, so that the plate 35 will lie fiat on the upper surface of the workpiece I6.

In the use and operation of this device the attachment is secured by means of the fastening members I8 to the lower side of the motor II. The guides I9 are disposed in parallel relation with the longitudinal axis of the drill` bit I5, and at a point rearwardly from the drill bit so that the latter may be positioned in the cutout 38, as shown in Figure 3.

The bar 24 is adjusted by the threaded shaft 28, and preferably Vone of the guide members is formed with graduations 40 which are correlated with the drill bit I5 so that the depth of the opening formed by the bit I5 can be accurately determined. In practice the bar 24 is adjusted so that the zero graduation will appear at the time the drill bit I5 is in contact with the workpiece. 'The drill may then-be moved inwardly of the workpiece to the limit provided by the collar 2|. If desired, the drill may be stopped at any point indicated by a selected graduation 40 so-that the attachment may provide a guide for the drill, and also serve as a depth gage to indicate the depth of the opening formed by the drill. After the hole has been drilled the springs 22 will assist in removing the drill bit; from the opening formed thereby.

The depth gauge also may be used to advantage with conventional electric vpowered hand drills whose housing I2 and chuck I4 are in a longitudinal line with motor II but whose handle I3 extends right angularly from the rest of the drill. Plate is provided with two pair of feet, 31 and 39, of equa1 length so that the plate 35 will keep the drill or countersink bit at right angles and also act as a steadying table, regardless as to whether workpiece I6 has a flat, concave or convex surface.

What I claim is:

1. In an electric hand drill, a stop for limiting the movement of the drill bit, comprising a base plate adapted for attachment to the hand drill, a pair of guide bars extending from said plate in parallelism with respect to said drill bit, a pair of tubular slide members slidable on said guide bars, a working engaging plate fixed to the outer ends of said slide members and disposed at right angles thereto, a threaded shaft rotatably carried by said base plate between and parallel to said guide bars, a connecting bar threadable on said shaft loosely engaging said slide members and means limiting the movement of said connecting bar on said slide members.

2. An attachment for a hand drill for limiting the movement of the drill bit into the work, comprising a base plate for attachment to the drill housing, a pair of guide bars carried by said plate disposed in parallel relation to the drill bit, a pair of slide members engaging said guide bars, a work engaging plate fixed to said slide members, a shaft rotatably carried by said base plate, a connecting bar slidably carried by said slide members, means for limiting the movement of said connecting bar on said slide members and means for adjustably securing said connecting bar on said shaft.

3. An attachment as set forth in claim 2, wherein said shaft is threaded and said connecting bar threadably engages said shaft.

4. An attachment for a hand drill for limiting the movement of the drill bit into the work, comprising a base plate for attachment to the drill housing, a pair of guide bars carried by said plate disposed in parallel relation to the drill bit, a pair of slide members engaging said guide bars, a work engaging plate fixed to said slide members, a connecting bar slidable on said slide members, means carried by said slide members for limiting the movement of said connecting member thereon, and a threaded shaft engaging said base plate and said connecting bar for adjustably fixing the distance therebetween.

DAVID N. GOLDBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,590,643 Neuwelt June 29, 1926 833,001 Press Oct. 9, 1906 712,367 Dummer Oct. 28, 1902 FOREIGN PATENTS Number Country Date 557,254 Great Britain Nov. 11, 1943 

